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<head><meta charset="utf-8"><title>design meetings during April · t-lang · Zulip Chat Archive</title></head>
<h2>Stream: <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/index.html">t-lang</a></h2>
<h3>Topic: <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html">design meetings during April</a></h3>

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<a name="192729489"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729489" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729489">(Apr 02 2020 at 21:32)</a>:</h4>
<p>So hey <span class="user-group-mention" data-user-group-id="1977">@T-lang</span>, let's talk about design meetings! We've got a list of potential topics for April in the paper, which is currently</p>
<ul>
<li>how to deal with type aliases and bounds, and especially the proposal <a href="https://github.com/rust-lang/rust/issues/69741" title="https://github.com/rust-lang/rust/issues/69741">#69741</a></li>
<li>unsafe code guidelines, how to integrate and make progress </li>
<li>“Copy out of references” — focus on use cases and inter-related problems -- I think this was <code>&amp;T</code> to <code>T</code> coercion where <code>T: Copy</code></li>
</ul>



<a name="192729523"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729523" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729523">(Apr 02 2020 at 21:32)</a>:</h4>
<p>I think I might add a few more such as</p>



<a name="192729575"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729575" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729575">(Apr 02 2020 at 21:32)</a>:</h4>
<p>cc <span class="user-mention" data-user-id="119009">@eddyb</span>  on type aliases &amp; bounds</p>



<a name="192729599"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729599" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729599">(Apr 02 2020 at 21:32)</a>:</h4>
<ul>
<li>Edition planning -- one of the things we're supposed to be doing is thinking about breaking changes for the edition, maybe we want to thinking a bit in advance. I remember the last time I thought about this I had a few thoughts of the kinds of things we might consider.</li>
</ul>



<a name="192729660"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729660" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729660">(Apr 02 2020 at 21:33)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> I would love to have the "copy out of references" discussion, and better understand the use cases there. Can I suggest that we schedule that one at a time that would allow enough prep time for folks who want a change there to supply some use cases or examples without feeling rushed?</p>



<a name="192729696"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729696" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729696">(Apr 02 2020 at 21:33)</a>:</h4>
<ul>
<li>TryInto and try functions and try blocks oh my (cc <span class="user-mention" data-user-id="125270">@scottmcm</span> in particular on that one)</li>
</ul>



<a name="192729779"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729779" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729779">(Apr 02 2020 at 21:34)</a>:</h4>
<p>I feel like UCG is sufficiently amorphous that the only discrete topic I can think of there is "what discrete topics are separable and able to be evaluated"?</p>



<a name="192729902"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729902" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729902">(Apr 02 2020 at 21:35)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> <span class="user-mention" data-user-id="119009">@eddyb</span> handed me: <a href="https://github.com/rust-lang/rust/pulls?q=is%3Aclosed+is%3Apr+author%3Aeddyb+is%3Aunmerged+type+alias+" title="https://github.com/rust-lang/rust/pulls?q=is%3Aclosed+is%3Apr+author%3Aeddyb+is%3Aunmerged+type+alias+">https://github.com/rust-lang/rust/pulls?q=is%3Aclosed+is%3Apr+author%3Aeddyb+is%3Aunmerged+type+alias+</a></p>



<a name="192729932"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729932" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729932">(Apr 02 2020 at 21:35)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> Also CC <span class="user-mention" data-user-id="127859">@Taylor Cramer</span> on the <code>try</code> family of items. And for that one, I would be happy to come prepared to discuss and evaluate alternatives there, and I've found myself increasingly open to changing my mind. I no longer have the objection I once did to <code>try</code> blocks, and my only point of contention is "what type do they have and how do we write that type", which I feel like is a narrower point conducive to collaborative solution-finding.</p>



<a name="192729956"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192729956" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192729956">(Apr 02 2020 at 21:35)</a>:</h4>
<p>All the type alias PRs are in those search results</p>



<a name="192730155"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730155" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730155">(Apr 02 2020 at 21:37)</a>:</h4>
<p>(Also, let me say that more strongly: I have found lately that I've actively <em>wanted</em> <code>try</code> blocks several times, so it's not just that I'm now neutral to them.)</p>



<a name="192730198"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730198" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730198">(Apr 02 2020 at 21:37)</a>:</h4>
<p>/me opens a separate thread for a related tangent.</p>



<a name="192730330"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730330" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730330">(Apr 02 2020 at 21:38)</a>:</h4>
<p>note that <a href="https://github.com/rust-lang/rust/issues/49441#issuecomment-421136550" title="https://github.com/rust-lang/rust/issues/49441#issuecomment-421136550">https://github.com/rust-lang/rust/issues/49441#issuecomment-421136550</a> is the issue we were using to track the 2018 stuff before it fell through the floor</p>



<a name="192730336"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730336" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730336">(Apr 02 2020 at 21:39)</a>:</h4>
<p>2018 burnout was real :(</p>



<a name="192730486"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730486" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730486">(Apr 02 2020 at 21:40)</a>:</h4>
<p>Sorry, I'm a bit afk actually, having kind of started this discussion off :)</p>



<a name="192730495"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730495" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730495">(Apr 02 2020 at 21:40)</a>:</h4>
<p>Didn't realize how late it was</p>



<a name="192730527"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730527" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730527">(Apr 02 2020 at 21:40)</a>:</h4>
<p>In terms of available dates in April, we have</p>
<ul>
<li>Apr 13</li>
<li>Apr 20</li>
<li>Apr 27</li>
</ul>



<a name="192730585"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192730585" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192730585">(Apr 02 2020 at 21:41)</a>:</h4>
<p>(Excluding next week)</p>



<a name="192828688"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192828688" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192828688">(Apr 03 2020 at 16:21)</a>:</h4>
<p>I'm guessing edition planning should be handled at <em>some</em> point during this design cycle</p>



<a name="192828695"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192828695" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192828695">(Apr 03 2020 at 16:21)</a>:</h4>
<p>given that its already April</p>



<a name="192828732"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192828732" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> pnkfelix <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192828732">(Apr 03 2020 at 16:21)</a>:</h4>
<p>but I don't think it will matter much if we do it in mid April or at end of April</p>



<a name="192829877"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/192829877" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#192829877">(Apr 03 2020 at 16:30)</a>:</h4>
<p>I would suggest 20th for the edition stuff, and 27th for the type alias stuff (since it ties into the edition)</p>



<a name="193378989"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193378989" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193378989">(Apr 08 2020 at 21:08)</a>:</h4>
<p><span class="user-mention" data-user-id="239881">@Josh Triplett</span> so see the available dates above</p>



<a name="193379147"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379147" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379147">(Apr 08 2020 at 21:10)</a>:</h4>
<p>I think discussing try seems good</p>



<a name="193379163"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379163" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379163">(Apr 08 2020 at 21:10)</a>:</h4>
<p>but there are a few different aspects to it</p>



<a name="193379173"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379173" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379173">(Apr 08 2020 at 21:10)</a>:</h4>
<p>I wonder if we can fit it all in one meeting?</p>



<a name="193379254"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379254" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379254">(Apr 08 2020 at 21:11)</a>:</h4>
<p>I'm thinking of:</p>



<a name="193379257"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379257" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379257">(Apr 08 2020 at 21:11)</a>:</h4>
<ul>
<li><code>Try</code> trait</li>
</ul>



<a name="193379263"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379263" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379263">(Apr 08 2020 at 21:11)</a>:</h4>
<ul>
<li>try blocks and ok-wrapping</li>
</ul>



<a name="193379309"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379309" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379309">(Apr 08 2020 at 21:12)</a>:</h4>
<ul>
<li>try functions and some of the details there</li>
</ul>



<a name="193379321"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379321" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379321">(Apr 08 2020 at 21:12)</a>:</h4>
<p>I've not read <span class="user-mention" data-user-id="256759">@boats</span>'s posts, but obviously i'd like for them to be present</p>



<a name="193379438"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379438" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379438">(Apr 08 2020 at 21:13)</a>:</h4>
<p>though not necessarily for the first point</p>



<a name="193379583"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379583" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379583">(Apr 08 2020 at 21:15)</a>:</h4>
<p>Hmm, I think doing </p>
<ul>
<li>13th -- something about try, maybe, but it depends if <span class="user-mention" data-user-id="125270">@scottmcm</span> and/or <span class="user-mention" data-user-id="256759">@boats</span> are available</li>
<li>20th -- Overall Edition planning - who will lead and can we narrow this topic?</li>
<li>27th -- type alias -- someone has to lead and gather data. I'm curious also if <span class="user-mention" data-user-id="119009">@eddyb</span> would be able to attend (<span class="user-mention" data-user-id="119009">@eddyb</span>, the meetings are at 12:00 Eastern time, so I think that would be 19:00 your time)</li>
</ul>



<a name="193379592"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379592" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379592">(Apr 08 2020 at 21:15)</a>:</h4>
<p>(On mondays)</p>



<a name="193379605"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379605" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379605">(Apr 08 2020 at 21:15)</a>:</h4>
<p>seems reasonable</p>



<a name="193379629"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379629" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379629">(Apr 08 2020 at 21:15)</a>:</h4>
<p>I would be happy to try and lead up the Edition a bit</p>



<a name="193379700"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379700" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379700">(Apr 08 2020 at 21:16)</a>:</h4>
<p>I would also be ok with putting off the type alias slightly further, if we think that's too many meetings and we won't be able to manage it</p>



<a name="193379701"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379701" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379701">(Apr 08 2020 at 21:16)</a>:</h4>
<p>it's fine I think</p>



<a name="193379710"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379710" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379710">(Apr 08 2020 at 21:16)</a>:</h4>
<p>i.e., we could do it first thing in may</p>



<a name="193379712"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379712" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379712">(Apr 08 2020 at 21:16)</a>:</h4>
<p>I would suggest that if we order it correctly, we could get through as much as we can in one meeting:<br>
1) <code>try</code> blocks and <code>Ok</code>-wrapping, for which as far as I an tell there aren't any remaining disagreements.<br>
2) <code>Try</code> trait: what do we need to complete in order to stabilize <code>try</code> blocks? This is more complicated, but not necessarily a source of massive disagreements, just technical difficulties.<br>
3) <code>try</code> functions and potential syntax there; this is likely to expand to encompass <code>-&gt; Result&lt;T, E&gt;</code> versus syntax proposals that hide <code>Result</code>, so let's put it last and if we run out of time that's OK.</p>



<a name="193379731"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379731" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379731">(Apr 08 2020 at 21:16)</a>:</h4>
<p>This sounds reasonable</p>



<a name="193379805"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379805" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379805">(Apr 08 2020 at 21:17)</a>:</h4>
<p>What do you think of that overall schedule? Also, can we discuss how the Edition planning might work</p>



<a name="193379810"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379810" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379810">(Apr 08 2020 at 21:17)</a>:</h4>
<p>I'm also wondering if there'd be any objection to <em>starting</em> on (1) and getting the <em>skeleton</em> of what needs to be solved for (2) in Thursday's meeting?</p>



<a name="193379828"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379828" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379828">(Apr 08 2020 at 21:17)</a>:</h4>
<p>are you referring to try blocks?</p>



<a name="193379836"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379836" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379836">(Apr 08 2020 at 21:18)</a>:</h4>
<p>I thkn that try blocks ok wrap <em>now</em></p>



<a name="193379875"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379875" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379875">(Apr 08 2020 at 21:18)</a>:</h4>
<p>so I don't think there's any real "work" to be done there</p>



<a name="193379877"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379877" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379877">(Apr 08 2020 at 21:18)</a>:</h4>
<p>Yes. Because if we end up resolving (1) <em>in</em> Thursday's meeting, and getting a skeleton for (2), then the design meeting on Monday could be much simpler.</p>



<a name="193379903"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379903" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379903">(Apr 08 2020 at 21:18)</a>:</h4>
<p>if we want to reach a decision, I could imagine that we create an issue with a summary of some of the pros/cons and do an fcp</p>



<a name="193379909"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379909" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379909">(Apr 08 2020 at 21:18)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> The "work" is effectively an explicit "are there any remaining objections, or any other blockers for <code>try</code> block stabilization other than the <code>Try</code> trait".</p>



<a name="193379911"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379911" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379911">(Apr 08 2020 at 21:18)</a>:</h4>
<p>to make it official</p>



<a name="193379928"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379928" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379928">(Apr 08 2020 at 21:18)</a>:</h4>
<p>and I think we could just do that today</p>



<a name="193379944"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379944" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379944">(Apr 08 2020 at 21:19)</a>:</h4>
<p>the problem is that I don't know that thu meeting necessary has all the folks presnt in it?</p>



<a name="193379948"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379948" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379948">(Apr 08 2020 at 21:19)</a>:</h4>
<p>but I guess it has enough</p>



<a name="193379953"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379953" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379953">(Apr 08 2020 at 21:19)</a>:</h4>
<p>that's also fine</p>



<a name="193379961"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379961" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379961">(Apr 08 2020 at 21:19)</a>:</h4>
<p>An FCP on an appropriate issue sounds good, sure. I wasn't sure which issue it should occur on. ;)</p>



<a name="193379973"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379973" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379973">(Apr 08 2020 at 21:19)</a>:</h4>
<p>I'd make a dedicated issue personally, and link to it</p>



<a name="193379984"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193379984" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193379984">(Apr 08 2020 at 21:19)</a>:</h4>
<p>I prefer to have an issue per decision</p>



<a name="193380014"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380014" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380014">(Apr 08 2020 at 21:19)</a>:</h4>
<p>link to it from <a href="https://github.com/rust-lang/rust/issues/31436" title="https://github.com/rust-lang/rust/issues/31436">https://github.com/rust-lang/rust/issues/31436</a> I mean, I guess</p>



<a name="193380016"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380016" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380016">(Apr 08 2020 at 21:19)</a>:</h4>
<p>Thinking about the overall schedule...</p>



<a name="193380099"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380099" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380099">(Apr 08 2020 at 21:20)</a>:</h4>
<p>type alias as in <code>impl Trait</code>?</p>



<a name="193380115"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380115" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380115">(Apr 08 2020 at 21:20)</a>:</h4>
<p>no</p>



<a name="193380130"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380130" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380130">(Apr 08 2020 at 21:21)</a>:</h4>
<p>that is referring to the long-standing issue that <code>type Foo&lt;T: Trait&gt; = ...</code> doesn't enforce <code>T: Trait</code></p>



<a name="193380140"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380140" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380140">(Apr 08 2020 at 21:21)</a>:</h4>
<p>Oh!</p>



<a name="193380161"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380161" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380161">(Apr 08 2020 at 21:21)</a>:</h4>
<p>the topic has been coming up again because of a recent PR to enforce "well-formedness conditions" in some cases</p>



<a name="193380172"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380172" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380172">(Apr 08 2020 at 21:21)</a>:</h4>
<p>we deferred it for Rust 2018</p>



<a name="193380176"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380176" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380176">(Apr 08 2020 at 21:21)</a>:</h4>
<p>which we <em>almost</em> fixed back for Rust 2018</p>



<a name="193380187"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380187" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380187">(Apr 08 2020 at 21:21)</a>:</h4>
<p>if we want to address it again, we thought we would review what happened last time</p>



<a name="193380188"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380188" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380188">(Apr 08 2020 at 21:21)</a>:</h4>
<p>but <em>gestures vaguely</em> stuff happened</p>



<a name="193380193"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380193" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380193">(Apr 08 2020 at 21:21)</a>:</h4>
<p>and talk about some of the options</p>



<a name="193380202"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380202" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380202">(Apr 08 2020 at 21:21)</a>:</h4>
<p>Is this also related to not being able to assume <code>&lt;T: Trait&gt;</code> in the <code>impl SomeType</code> block of a type, even if the data type implies that <code>T: Trait</code>?</p>



<a name="193380251"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380251" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380251">(Apr 08 2020 at 21:22)</a>:</h4>
<p>I don't think so</p>



<a name="193380261"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380261" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380261">(Apr 08 2020 at 21:22)</a>:</h4>
<p>I think you're referring to <em>implied bounds</em></p>



<a name="193380269"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380269" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380269">(Apr 08 2020 at 21:22)</a>:</h4>
<p>there actually is a relationship</p>



<a name="193380278"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380278" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380278">(Apr 08 2020 at 21:22)</a>:</h4>
<p>but it's not .. direct?</p>



<a name="193380280"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380280" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380280">(Apr 08 2020 at 21:22)</a>:</h4>
<p>this is about <code>type Foo = ...;</code> not type-checking <code>...</code> at all at the definition site</p>



<a name="193380281"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380281" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380281">(Apr 08 2020 at 21:22)</a>:</h4>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380261" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380261">said</a>:</p>
<blockquote>
<p>I think you're referring to <em>implied bounds</em></p>
</blockquote>
<p>I think you're right, yeah.</p>



<a name="193380312"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380312" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380312">(Apr 08 2020 at 21:23)</a>:</h4>
<p>and also use sites don't see the bounds at all, just the <code>...</code> part (the "RHS")</p>



<a name="193380372"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380372" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380372">(Apr 08 2020 at 21:23)</a>:</h4>
<p>There is a relationship in that one way to "rationalize" today's behavior is to imagine that there's an implied where clause that says the RHS if well-formed, which is a kind of "implied bound".</p>



<a name="193380389"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380389" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380389">(Apr 08 2020 at 21:24)</a>:</h4>
<p>but it's not a "real relationship"</p>



<a name="193380461"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380461" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380461">(Apr 08 2020 at 21:24)</a>:</h4>
<p>anyway <span class="user-mention" data-user-id="116009">@nikomatsakis</span> can handle this, ping me if you have any questions for me specifically (trying not to multitask too much :P)</p>



<a name="193380462"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380462" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380462">(Apr 08 2020 at 21:24)</a>:</h4>
<p>( another relationship is that continued progress around chalk is related )</p>



<a name="193380466"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380466" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380466">(Apr 08 2020 at 21:24)</a>:</h4>
<p>Alright. So, that seems like a reasonable thing to put on the agenda, and I'll be interested to listen and hear many things about traits and types and inference that I likely don't know. :)</p>



<a name="193380492"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380492" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380492">(Apr 08 2020 at 21:24)</a>:</h4>
<p>it seems good to revisit it</p>



<a name="193380500"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380500" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380500">(Apr 08 2020 at 21:24)</a>:</h4>
<p>So, the three proposals sound good to me.</p>



<a name="193380502"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380502" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380502">(Apr 08 2020 at 21:24)</a>:</h4>
<p>but let's talk a bit about the edition meeting</p>



<a name="193380509"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380509" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380509">(Apr 08 2020 at 21:25)</a>:</h4>
<p>what's needed to make that productive</p>



<a name="193380514"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380514" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380514">(Apr 08 2020 at 21:25)</a>:</h4>
<p>what I have in mind is</p>



<a name="193380542"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380542" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380542">(Apr 08 2020 at 21:25)</a>:</h4>
<p>We should make a document of "things we might want to change in an edition", and give people plenty of time to contribute to it before a meeting, I think...</p>



<a name="193380552"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380552" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380552">(Apr 08 2020 at 21:25)</a>:</h4>
<p>(1) go back over 'ergonomic initiative' and other stuff that didn't make it for Rust 2018 (which includes the type alias stuff) and try to write out some of the potential edition implications</p>



<a name="193380563"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380563" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380563">(Apr 08 2020 at 21:25)</a>:</h4>
<p>yes</p>



<a name="193380567"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380567" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380567">(Apr 08 2020 at 21:25)</a>:</h4>
<p>I am basically imagining creating such a doc and starting to fill it out</p>



<a name="193380570"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380570" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380570">(Apr 08 2020 at 21:25)</a>:</h4>
<p>and trying to do that early</p>



<a name="193380576"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380576" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380576">(Apr 08 2020 at 21:26)</a>:</h4>
<p>That sounds good to me.</p>



<a name="193380620"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380620" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380620">(Apr 08 2020 at 21:26)</a>:</h4>
<p>I think we should also include  things like "change of defaults"</p>



<a name="193380635"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380635" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380635">(Apr 08 2020 at 21:26)</a>:</h4>
<p>I'm going to take a few minutes and write up a dedicated issue for <code>try</code> block <code>Ok</code>-wrapping.</p>



<a name="193380637"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380637" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380637">(Apr 08 2020 at 21:26)</a>:</h4>
<p>i.e., I would include the "unsafe ops in unsafe fns"</p>



<a name="193380641"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380641" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380641">(Apr 08 2020 at 21:26)</a>:</h4>
<p>(we had some discussion of whether we might switch the default there)</p>



<a name="193380656"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380656" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380656">(Apr 08 2020 at 21:26)</a>:</h4>
<p>I think it'd be good to have a master list that we can revisit and keep an eye on</p>



<a name="193380660"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380660" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380660">(Apr 08 2020 at 21:26)</a>:</h4>
<p>and use to drive our efforts</p>



<a name="193380669"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380669" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380669">(Apr 08 2020 at 21:26)</a>:</h4>
<p>so our goal should be to produce that, and we should start the list <em>now</em></p>



<a name="193380694"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380694" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380694">(Apr 08 2020 at 21:27)</a>:</h4>
<p>that is, while you do that, I will create a paper document and start adding stuff</p>



<a name="193380700"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380700" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380700">(Apr 08 2020 at 21:27)</a>:</h4>
<p>We should also include, in the list, things we <em>don't</em> plan to do but that someone might expect. For instance, someone on internals recently suggested killing <code>ref</code> and <code>ref mut</code> in an edition, which, let's not. ;)</p>



<a name="193380730"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380730" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380730">(Apr 08 2020 at 21:27)</a>:</h4>
<p>heh. Yeah, I'm ok waiting on that (although I don't find I use them anymore)</p>



<a name="193380747"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380747" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380747">(Apr 08 2020 at 21:27)</a>:</h4>
<p>I'd like to err on the side of completeness, rather than prioritizing the list of "things we want to do" over "things we don't want to do".</p>



<a name="193380750"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380750" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380750">(Apr 08 2020 at 21:27)</a>:</h4>
<p>btw</p>



<a name="193380801"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380801" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380801">(Apr 08 2020 at 21:28)</a>:</h4>
<p>I just happened to click on that internals thread and see your post</p>



<a name="193380824"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380824" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380824">(Apr 08 2020 at 21:28)</a>:</h4>
<p>that issue around <code>&amp;u32</code> is definitely one of the key motivators for the <code>&amp;T -&gt; T</code> coercions where <code>T: Copy</code></p>



<a name="193380827"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380827" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380827">(Apr 08 2020 at 21:28)</a>:</h4>
<p>but I guess you know that :)</p>



<a name="193380829"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380829" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380829">(Apr 08 2020 at 21:28)</a>:</h4>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380801" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380801">said</a>:</p>
<blockquote>
<p>I just happened to click on that internals thread and see your post</p>
</blockquote>
<p>I find myself wishing I could have written the example that I did back when we were debating this.</p>



<a name="193380843"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380843" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380843">(Apr 08 2020 at 21:28)</a>:</h4>
<p>that issue was extensively discussed, fwiw</p>



<a name="193380874"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380874" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380874">(Apr 08 2020 at 21:29)</a>:</h4>
<p>but maybe not extensively enough :)</p>



<a name="193380899"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380899" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380899">(Apr 08 2020 at 21:29)</a>:</h4>
<p>I remember, vividly. I just don't remember any examples coming up that demonstrated, on a practical level,  the "rustc can't help me find the root error anymore" problem.</p>



<a name="193380913"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380913" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380913">(Apr 08 2020 at 21:29)</a>:</h4>
<p>Yeah, I mean, I think we just didn't do the follow-up</p>



<a name="193380918"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380918" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380918">(Apr 08 2020 at 21:29)</a>:</h4>
<p>All the more reason to do it now!</p>



<a name="193380970"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380970" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380970">(Apr 08 2020 at 21:30)</a>:</h4>
<p><em>nod</em></p>



<a name="193380991"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380991" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380991">(Apr 08 2020 at 21:30)</a>:</h4>
<p>I guess I disagree with your assertion that suggesting <code>*x</code> is wrong</p>



<a name="193380997"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193380997" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193380997">(Apr 08 2020 at 21:30)</a>:</h4>
<p>but let's not get too far off topic</p>



<a name="193381007"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381007" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381007">(Apr 08 2020 at 21:30)</a>:</h4>
<p>(in particular, the edit I make in practice is adding a <code>*x</code>)</p>



<a name="193381011"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381011" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381011">(Apr 08 2020 at 21:30)</a>:</h4>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380824" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380824">said</a>:</p>
<blockquote>
<p>that issue around <code>&amp;u32</code> is definitely one of the key motivators for the <code>&amp;T -&gt; T</code> coercions where <code>T: Copy</code></p>
</blockquote>
<p>Thank you for pointing that out; that helps me understand a bit better. Needs some further thought.</p>



<a name="193381019"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381019" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381019">(Apr 08 2020 at 21:30)</a>:</h4>
<p>(not that I'm super happy about that)</p>



<a name="193381042"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381042" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381042">(Apr 08 2020 at 21:31)</a>:</h4>
<p>that's on our list, but I think we can discuss those things post April</p>



<a name="193381071"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381071" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381071">(Apr 08 2020 at 21:31)</a>:</h4>
<p>I would love to talk with you and introspect a bit on your feeling of "not that I'm super happy about that", to understand why that's the fix you tend to make in practice even if you don't want to.</p>



<a name="193381174"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381174" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381174">(Apr 08 2020 at 21:32)</a>:</h4>
<p>yes, I'd enjoy that</p>



<a name="193381186"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381186" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381186">(Apr 08 2020 at 21:32)</a>:</h4>
<p>oops dang it</p>



<a name="193381194"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381194" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381194">(Apr 08 2020 at 21:32)</a>:</h4>
<p>I had a draft of the final schedule</p>



<a name="193381200"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381200" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381200">(Apr 08 2020 at 21:32)</a>:</h4>
<p>And yes, this is getting a little off-topic. ;)<br>
The slightly more comedic version I considered, when trying to explain my reaction to rustc's errors: <br>
"Your foundation is broken. Would you like to add a flying buttress?" No, rustc, I'd like to fix the foundation, not patch around the original error by propping up the wobbly result the other way.</p>



<a name="193381206"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381206" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381206">(Apr 08 2020 at 21:32)</a>:</h4>
<p>and I stupidly did select-all delete and lost it</p>



<a name="193381208"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381208" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381208">(Apr 08 2020 at 21:32)</a>:</h4>
<p>let me rewrite it :)</p>



<a name="193381547"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381547" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381547">(Apr 08 2020 at 21:36)</a>:</h4>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193381007" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193381007">said</a>:</p>
<blockquote>
<p>(in particular, the edit I make in practice is adding a <code>*x</code>)</p>
</blockquote>
<p>I almost always try to add <code>&amp;</code> to a pattern  before I find it prettier than <code>*</code> (and for more than 1 use, it's less noise since only the pattern needs to change, not the uses)</p>



<a name="193381647"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381647" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381647">(Apr 08 2020 at 21:37)</a>:</h4>
<p><span class="user-mention" data-user-id="119009">@eddyb</span> Agreed. Though adding <code>*</code> to the match scrutinee can avoid the need to add <code>&amp;</code> to a half-dozen patterns; for some reason I don't tend to find <em>that</em> intuitive to reach for, though.</p>



<a name="193381695"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381695" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> eddyb <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381695">(Apr 08 2020 at 21:37)</a>:</h4>
<p>I mean <code>|&amp;x| x</code> instead of <code>|x| *x</code>, where the <code>*</code> would be <em>later</em> than the <code>&amp;</code></p>



<a name="193381698"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381698" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381698">(Apr 08 2020 at 21:37)</a>:</h4>
<p>I think I have some kind of incorrect associations regarding <code>match *x</code>, such that it "feels" like that's going to surprise me by making a copy I don't expect.</p>



<a name="193381745"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381745" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381745">(Apr 08 2020 at 21:38)</a>:</h4>
<p><span class="user-mention" data-user-id="119009">@eddyb</span> (I know, and that's what niko meant too. I was referring to a third possibility there.)</p>



<a name="193381780"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381780" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381780">(Apr 08 2020 at 21:38)</a>:</h4>
<p><span class="user-mention" data-user-id="239881">@Josh Triplett</span> how does <a href="https://gist.github.com/nikomatsakis/6993a31554708c1e84282d90f15fbb0b" title="https://gist.github.com/nikomatsakis/6993a31554708c1e84282d90f15fbb0b">this gist</a> look to you?</p>



<a name="193381856"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381856" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Amanieu <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381856">(Apr 08 2020 at 21:39)</a>:</h4>
<p>Does <code>asm!</code> need a design meeting to move forward? Or is it blocked on something else?</p>



<a name="193381879"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381879" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381879">(Apr 08 2020 at 21:39)</a>:</h4>
<p>I don't believe it does.</p>



<a name="193381895"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381895" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381895">(Apr 08 2020 at 21:39)</a>:</h4>
<p>Well, let me revisit that</p>



<a name="193381929"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193381929" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193381929">(Apr 08 2020 at 21:40)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> Minor request: could you change "try functions" to "function-level try"? I feel like the former predisposes us towards the syntax <code>try fn</code>, while the latter feels more syntax-agnostic to me as a description.</p>



<a name="193382022"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382022" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382022">(Apr 08 2020 at 21:40)</a>:</h4>
<p><span class="user-mention" data-user-id="143274">@Amanieu</span> so here is why I am revisiting that</p>



<a name="193382033"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382033" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382033">(Apr 08 2020 at 21:40)</a>:</h4>
<p><em>in general</em>, I think it'd be super healthy for us</p>



<a name="193382040"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382040" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382040">(Apr 08 2020 at 21:40)</a>:</h4>
<p>if when we are introducing a major new piece of design</p>



<a name="193382044"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382044" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382044">(Apr 08 2020 at 21:40)</a>:</h4>
<p>we spend a design meeting on it</p>



<a name="193382054"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382054" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382054">(Apr 08 2020 at 21:41)</a>:</h4>
<p>to have somebody kind of walk over the RFC and lay out what it does</p>



<a name="193382061"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382061" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382061">(Apr 08 2020 at 21:41)</a>:</h4>
<p>even if we've all already read it</p>



<a name="193382064"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382064" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382064">(Apr 08 2020 at 21:41)</a>:</h4>
<p>and kind of know</p>



<a name="193382074"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382074" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382074">(Apr 08 2020 at 21:41)</a>:</h4>
<p>it produces a video that we can publish</p>



<a name="193382098"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382098" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382098">(Apr 08 2020 at 21:41)</a>:</h4>
<p>I also question whether it's ever <em>really</em> true that everybody has had time to catch up</p>



<a name="193382100"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382100" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382100">(Apr 08 2020 at 21:41)</a>:</h4>
<p>(We did actually spend a big piece of a lang meeting on <code>asm!</code>, by the way, when it first came up.)</p>



<a name="193382113"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382113" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382113">(Apr 08 2020 at 21:41)</a>:</h4>
<p>well, we did, but that's different</p>



<a name="193382123"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382123" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382123">(Apr 08 2020 at 21:41)</a>:</h4>
<p>also, I don't know that we really did</p>



<a name="193382124"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382124" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382124">(Apr 08 2020 at 21:41)</a>:</h4>
<p>I'm not arguing that we shouldn't spend another. ;)</p>



<a name="193382147"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382147" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382147">(Apr 08 2020 at 21:41)</a>:</h4>
<p>in particular, the final RFC didn't exist</p>



<a name="193382198"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382198" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382198">(Apr 08 2020 at 21:42)</a>:</h4>
<p>we talked about <em>whether</em> to do <code>asm!</code>, but not so much about the actual proposal, and the discussion that arose during the course of it, and so forth</p>



<a name="193382215"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382215" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382215">(Apr 08 2020 at 21:42)</a>:</h4>
<p>all of that said, I'm not sure it's the best use of time this month</p>



<a name="193382228"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382228" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382228">(Apr 08 2020 at 21:42)</a>:</h4>
<p>Ah, I see. You're suggesting that in general we should spend a meeting reviewing the details of a (seemingly) completed RFC?</p>



<a name="193382229"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382229" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382229">(Apr 08 2020 at 21:42)</a>:</h4>
<p>I just think in general it'd be cool to be doing more presentations like that</p>



<a name="193382238"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382238" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382238">(Apr 08 2020 at 21:42)</a>:</h4>
<p>I kind of think so, yes</p>



<a name="193382254"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382254" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382254">(Apr 08 2020 at 21:43)</a>:</h4>
<p>I think that's a good idea, especially if we manage to move more to the "approve delegating this" and later "approve the result of the delegated team" model.</p>



<a name="193382256"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382256" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382256">(Apr 08 2020 at 21:43)</a>:</h4>
<p>or at least I think it's a healthy thing to do</p>



<a name="193382260"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382260" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382260">(Apr 08 2020 at 21:43)</a>:</h4>
<p>I don't think I'd say it should be "required"</p>



<a name="193382268"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382268" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382268">(Apr 08 2020 at 21:43)</a>:</h4>
<p>exactly</p>



<a name="193382279"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382279" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382279">(Apr 08 2020 at 21:43)</a>:</h4>
<p>(it depends, I think, on the scope of the RFC etc)</p>



<a name="193382310"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382310" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382310">(Apr 08 2020 at 21:44)</a>:</h4>
<p>Schedule looks good to me other than that one nit.</p>



<a name="193382433"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382433" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Amanieu <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382433">(Apr 08 2020 at 21:45)</a>:</h4>
<p>There's also the distinction between replacing <code>asm!</code> in nightly and stabilizing it. How much should the former be blocked on lang team approval (which is definitely needed for the latter).</p>



<a name="193382913"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382913" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382913">(Apr 08 2020 at 21:50)</a>:</h4>
<p>so we discussed this just a bit in privmsg but to bring it here</p>



<a name="193382920"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382920" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382920">(Apr 08 2020 at 21:50)</a>:</h4>
<p>that's actually a more interesting question than I thought at first :P</p>



<a name="193382943"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382943" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382943">(Apr 08 2020 at 21:51)</a>:</h4>
<p>I think in my ideal world we would tilt ourselves towards permitting stuff to land before a design is "ready"</p>



<a name="193382960"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382960" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382960">(Apr 08 2020 at 21:51)</a>:</h4>
<p>this <em>was</em> the idea of creating project groups</p>



<a name="193382970"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382970" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382970">(Apr 08 2020 at 21:51)</a>:</h4>
<p>that we clear up the "intent to explore this" first</p>



<a name="193382975"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382975" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382975">(Apr 08 2020 at 21:51)</a>:</h4>
<p>and then people can land etc etc</p>



<a name="193382979"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382979" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382979">(Apr 08 2020 at 21:51)</a>:</h4>
<p>and the RFC could indeed come after the impl is done</p>



<a name="193382991"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382991" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382991">(Apr 08 2020 at 21:51)</a>:</h4>
<p>and it is just laying out the design that we wound up with</p>



<a name="193382998"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193382998" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193382998">(Apr 08 2020 at 21:51)</a>:</h4>
<p>(ideally, they co-evolve, as I think happened here)</p>



<a name="193383073"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193383073" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193383073">(Apr 08 2020 at 21:52)</a>:</h4>
<p>so I think in this case what we really need is to resolve <a href="https://github.com/rust-lang/rfcs/pull/2836" title="https://github.com/rust-lang/rfcs/pull/2836">https://github.com/rust-lang/rfcs/pull/2836</a>, and I don't think a design meeting is the best venue for that ultimately</p>



<a name="193383294"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193383294" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193383294">(Apr 08 2020 at 21:54)</a>:</h4>
<p><span class="user-mention" data-user-id="239881">@Josh Triplett</span> how is this :)</p>
<blockquote>
<h1>April 13 -- Try blocks, try traits, functions that try, oh my!</h1>
</blockquote>



<a name="193383312"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193383312" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193383312">(Apr 08 2020 at 21:54)</a>:</h4>
<p>I like my whimsical rhyme ;)</p>



<a name="193383975"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193383975" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> boats <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193383975">(Apr 08 2020 at 22:02)</a>:</h4>
<p>i can attend any week</p>



<a name="193384772"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193384772" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193384772">(Apr 08 2020 at 22:10)</a>:</h4>
<p><span class="user-mention" data-user-id="116009">@nikomatsakis</span> I just realized something else that needs adding to the <code>try</code> design meeting, which I'd suggest covering after the <code>Try</code> trait and before functions that try: the error return mechanism from try blocks and functions that try. <code>fail err;</code>, <code>throw err;</code>, <code>raise err;</code>, <code>Err(err)?;</code>...</p>



<a name="193384815"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193384815" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193384815">(Apr 08 2020 at 22:11)</a>:</h4>
<p>Still likely to lead to syntax disputes, but less so than the syntax for functions that try.</p>



<a name="193411186"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193411186" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193411186">(Apr 09 2020 at 06:26)</a>:</h4>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193379583" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193379583">said</a>:</p>
<blockquote>
<ul>
<li>13th -- something about try, maybe, but it depends if scottmcm and/or boats are available</li>
</ul>
</blockquote>
<p>I can make the 13th.  Anything particular you'd like me to prepare for it?</p>



<a name="193411202"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193411202" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193411202">(Apr 09 2020 at 06:26)</a>:</h4>
<p><span class="user-mention silent" data-user-id="239881">Josh Triplett</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380700" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193380700">said</a>:</p>
<blockquote>
<p>We should also include, in the list, things we <em>don't</em> plan to do but that someone might expect. For instance, someone on internals recently suggested killing <code>ref</code> and <code>ref mut</code> in an edition, which, let's not. ;)</p>
</blockquote>
<p>I think that's a great idea to avoid the free-for-all; and I'm in full agreement re. "let's not" for <code>ref mut?</code></p>



<a name="193411468"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193411468" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193411468">(Apr 09 2020 at 06:31)</a>:</h4>
<p><span class="user-mention silent" data-user-id="239881">Josh Triplett</span> <a href="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193384772" title="#narrow/stream/213817-t-lang/topic/design.20meetings.20during.20April/near/193384772">said</a>:</p>
<blockquote>
<p><span class="user-mention silent" data-user-id="116009">nikomatsakis</span> I just realized something else that needs adding to the <code>try</code> design meeting, which I'd suggest covering after the <code>Try</code> trait and before functions that try: the error return mechanism from try blocks and functions that try. <code>fail err;</code>, <code>throw err;</code>, <code>raise err;</code>, <code>Err(err)?;</code>...</p>
</blockquote>
<p>This also ties into the edition as we have to use that mechanism for any keyword; <code>throw err;</code> seems more unlikely now that more macros named <code>throw!(err);</code> exist, so <code>fail err;</code> seems more plausible now I think.</p>



<a name="193411966"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193411966" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193411966">(Apr 09 2020 at 06:38)</a>:</h4>
<p>I think that what we might want to do with <code>throw</code> comes into the trait discussions as well.  Both in the obvious way that we need to desugar it to something, but also in that if one of the <code>Try</code> rewrite goals is that it "remembers" result- or option-ness from a <code>?</code> then we'd need to figure out how to colour a <code>throw</code> properly.</p>



<a name="193412594"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193412594" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193412594">(Apr 09 2020 at 06:48)</a>:</h4>
<p>In a function that returns an Option, I would think we'd just want <code>fail;</code> with no arguments.</p>



<a name="193413185"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193413185" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193413185">(Apr 09 2020 at 06:58)</a>:</h4>
<p>Hmm, interesting.  I agree, but I also think that <code>bikeshed;</code> and <code>bikeshed ();</code> so the same thing here, as they do with <code>return</code> and <code>break</code>.  And I think those two statements contradict each other</p>



<a name="193413220"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193413220" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> Josh Triplett <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193413220">(Apr 09 2020 at 06:59)</a>:</h4>
<p>That would probably depend on how it desugars.</p>



<a name="193416212"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416212" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416212">(Apr 09 2020 at 07:41)</a>:</h4>
<p>Unbaked idea that I wanted to write down because I'm forgetful: right now the error-conversion we do for results is part of the <code>?</code> desugar.  But AFAICT that's currently indistinguishable from it happening at function-level, since there can only be one "level" of <code>?</code>s in a function.  So if we wanted to we could potentially _not_ to the error-conversion inside <code>try</code>, to reduce the type annotation requirements.  (For the whole "I'd like to not have to annotate <code>try { a? + b? }</code> and have it just use the same carrier and error type" conversation.)  Though I suppose that has the obvious downside that IIFEs and <code>try{}</code>s would do different things, so maybe it's bad.</p>



<a name="193416348"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416348" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416348">(Apr 09 2020 at 07:43)</a>:</h4>
<p><span class="user-mention" data-user-id="125270">@scottmcm</span> Seems like a good idea to move the <code>From::from</code> part of lowering into something specific to <code>Result&lt;_, _&gt;</code> if possible so that users can have a choice about that conversion for their own types</p>



<a name="193416383"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416383" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416383">(Apr 09 2020 at 07:44)</a>:</h4>
<p>Except that's not what you're saying <span aria-label="slight smile" class="emoji emoji-1f642" role="img" title="slight smile">:slight_smile:</span></p>



<a name="193416426"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416426" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416426">(Apr 09 2020 at 07:44)</a>:</h4>
<p>/me is tired...</p>



<a name="193416530"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416530" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416530">(Apr 09 2020 at 07:45)</a>:</h4>
<p>It's still a good idea :P  And fits well in the trait split I think we're heading towards</p>



<a name="193416759"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193416759" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> centril <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193416759">(Apr 09 2020 at 07:47)</a>:</h4>
<p>Also, <span class="user-mention" data-user-id="198590">@comex</span>'s point regarding perf seems like something we should keep in mind and avoid making MIR optimizations have too much of a hard time with <code>?</code></p>



<a name="193417065"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193417065" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> scottmcm <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193417065">(Apr 09 2020 at 07:51)</a>:</h4>
<p>My current thought is that we should have a <code>TryBlock</code> trait with an associated type for the continue-normally path, because that gives us the "you get a predictable type from <code>x?</code>" and "you can flow type information backwards into a <code>try{ Default::default() }</code>" things that are why we picked the current Try design.  But that for the splitting-and-error-handling stuff we should use a separate trait -- like the one in the original Try RFC design -- to allow the implementation to choose with which types it's willing to interoperate.</p>



<a name="193622359"></a>
<h4><a href="https://rust-lang.zulipchat.com#narrow/stream/213817-t-lang/topic/design%20meetings%20during%20April/near/193622359" class="zl"><img src="https://rust-lang.github.io/zulip_archive/assets/img/zulip.svg" alt="view this post on Zulip" style="width:20px;height:20px;"></a> nikomatsakis <a href="https://rust-lang.github.io/zulip_archive/stream/213817-t-lang/topic/design.20meetings.20during.20April.html#193622359">(Apr 10 2020 at 21:55)</a>:</h4>
<p>Update: given that there's been a lot of discussion around try, we opted to push the meeting back a bit to let things and opinions settle down. For now the "try meeting" is tentatively scheduled for May 4, but we can revisit as we think about meetings for May later on. <span aria-label="heart" class="emoji emoji-2764" role="img" title="heart">:heart:</span></p>



<hr><p>Last updated: Aug 07 2021 at 22:04 UTC</p>
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